1. Technical Field
The present disclosure relates generally to apparatus and methods for thermally and chemically converting waste products, such as municipal waste, into an ignitable gas stream. More particularly, the disclosure relates to improved modular apparatus for the controlled gasification and thermal conversion of waste products into a combustible gas, and for using the combustible gas a fuel source to produce electricity, or other useful energy.
2. Background
Waste converting thermal oxidation systems are known. For example, U.S. Pat. No. 4,941,415, which is hereby incorporated by reference, discloses an example of such a system. In general, municipal waste, or waste collected from residential, commercial, and some industrial and government facilities, is appropriately sorted, dried, and then loaded into a primary combustion chamber. The primary combustion chamber is typically sealed, and the waste ignited, to create a stream of combustible gas in the air-deprived environment of the primary combustion chamber. The combustible gas is typically mixed with additional combustible gas and channeled to a secondary combustion chamber where it is burned to generate thermal energy.
It is also known to arrange a plurality of primary chambers and combine the combustible gas effluent output into a single secondary combustion chamber. For example, U.S. Pat. No. 6,439,135, which is hereby incorporated by reference, discloses one such arrangement.
However, existing systems suffer from many drawbacks that make their operation inefficient, expensive, and potentially harmful to the environment. For example, existing systems often require pre-treatment of waste, such as sorting and drying, which require additional labor, operator attention, and costs. Other systems require significant amounts of fuel to ignite the waste and begin and sustain combustion. Another drawback of existing systems is the loss of heat and thermal energy that lowers the efficiency and output of the waste-to-energy conversion. Further, existing systems that do not operate in optimal ranges may exhibit emissions problems such as particulates, NOx, many toxic volatile metals, and dioxins/furans.
Existing systems also lack the control parameters for monitoring and controlling the production from gasification chambers, the modeling of said production of gases necessary for coordination to energy extraction, for venting the exhaust to atmosphere, or for energy generation, or the emissions discharged to the atmosphere. Many existing systems lack the ability to provide the foundation for scalability of the waste-to-energy conversion process. Finally, existing systems lack the ability to provide guaranteed energy generation when deficiencies of operation occur.
What is needed, therefore, is a controlled (starved) air gasification process, which thermally converts waste products into a combustible gas while eliminating or reducing the above-noted, and other, drawbacks. For example, the presently disclosed system provides, among other things, the control parameters for monitoring and controlling the production from gasification chambers, the modeling of said production for coordination to energy generation, for monitoring emissions discharged to the atmosphere, unique design and operation attributes that address the issues related to technology scale-up by incorporating a modular design and unique configuration of both Primary and Secondary Combustion design, as well as providing guaranteed energy generation when deficiencies of operation occur.